1. Field of the Invention
The present invention generally relates to a printing system, and particularly to a printer provided with a cutting section for automatically cutting a continuous printing paper or web. The present invention also relates to a cutter capable of being incorporated in a printer.
2. Description of the Related Art
In conventional printers, a cutting section is provided for automatically cutting a printing paper or web, after a printing section prints on printing paper continuously fed thereto, so as to cut off a printed length from an unprinted length. Such a printer with automatic cutter has been widely used as a printer adapted to be incorporated in a cash register, a portable terminal unit, and so on, wherein the cutting section is generally provided with a fixed blade and a movable blade, which cooperate with each other to cut a printing paper or web, and a drive mechanism for driving the movable blade for a cutting operation. In particular, it is conventional for a paper cutter as a self-contained apparatus, which is provided with a fixed blade and a movable blade unit including a movable blade and a blade drive mechanism, to be arranged downstream of the printing section of the printer as seen in a paper feeding direction.
In the conventional printer with automatic cutter, an openable/closable frame structure (generally called as a clamshell structure) is used, which includes a first frame member carrying a roll-type printing paper or web and a second frame member joined relatively pivotably with the first frame member and cooperating with the first frame member to define a web receiving space, and the movable blade of the cutting section is disposed on the first frame member as a stationary member, while the fixed blade of the cutting section is disposed on the second frame member as an openable/closable member (see, e.g., Japanese Unexamined Patent Publication (Kokai) No. 2000-61881 (JP2000-61881A)). In this known printer, the fixed blade and the movable blade in the cutting section are arranged to be shiftable relative to each other between a cooperative mutually-adjoining position (where the cutting operation can be performed) and an uncooperative mutually-remote position.
The clamshell structure as described above has been used in a thermal printer, provided with a heat-sensitive printing section including a thermal head and a platen, to facilitate the supply or exchange of a printing web (or a heat-sensitive paper). For example, in the printer as described in JP2000-61881A, the thermal head is mounted on the first frame member as a stationary base for carrying the web, while the platen is mounted on the second frame member as a pivoted cover for opening or closing the web receiving space, so as to constitute an openable/closable printing section. In this arrangement, the first frame member is fixedly or stationarily placed to specify an operative printing point, and the second frame member is shiftably or pivotably placed in relation to the operative printing point. The movable blade unit including the movable blade in the cutting section is disposed on the first frame member in close proximity to the thermal head and downstream of the thermal head as seen in the paper feeding direction, and the fixed blade in the cutting section is disposed on the second frame member in close proximity to the platen and downstream of the platen as seen in the paper feeding direction.
The thermal printer including the openable/closable printing section has an advantage in that a new printing paper or web as supplied or exchanged is readily set into a stand-by state by opening the frame members to make the thermal head and the platen fully remote from each other, then placing a leading end length of the printing paper along the thermal head or the platen, and thereafter closing the frame members. Also, the printer of JP2000-61881A has a further advantage in that, since the fixed blade and the movable blade in the cutting section are located at the mutually-remote position by opening the frame members and thereafter located at the mutually-adjoining position by closing the frame members, the leading end length of the printing paper is readily placed between the fixed and movable blades.
Conventionally, the cutting section of the printer with automatic cutter is constituted such that the fixed blade is disposed in closer proximity to the printing section than the movable blade (i.e., disposed at the inner side of the movable blade) when the fixed and movable blades are in the mutually-adjoining position, as described in JP2000-61881A. According to this blade arrangement, the unprinted length of the printing paper after being cut by the cutting section can stand by for a subsequent printing process in a condition where the leading end of the cut unprinted length is placed adjacent to the cutting edge of the fixed blade. In particular, in the case where the printing web is used, the remaining curl of the web tends to facilitate placing of the leading end of the cut unprinted web adjacent to the cutting edge. When the leading end of the cut unprinted paper is placed adjacent to the cutting edge, interference between the leading end and the fixed blade upon starting a subsequent printing process can be avoided, and thus the printing process can proceed smoothly.
As explained above, the conventional printer with automatic cutter is generally provided with the movable blade unit as a self-contained apparatus, which serves as the movable blade in the cutting section and is arranged downstream of the printing section as seen in the paper feeding direction. The movable blade unit generally has a relatively large outside dimension, which may make it difficult to reduce the overall size of the printer.
Also, as explained above, the conventional printer adopting the clamshell structure is constituted such that the fixed blade mounted on the second frame member as a pivoted cover is disposed inside of the movable blade mounted on the first frame member as a stationary base, when the fixed and movable blades are in the mutually-adjoining position. Thus, in the case where the printing paper becomes unintentionally jammed between the fixed blade and the movable blade during a paper cutting process to cause the malfunction of the movable blade, it is difficult to pivotally shift the second frame member relative to the first frame member while in the jamming condition, because the movable blade lies adjacent to the outside of the fixed blade. Therefore, in order to eliminate the jamming condition, it is necessary to forcibly retract the movable blade into the movable blade unit by, e.g., manually actuating the drive source in the movable blade unit. However, such a manual operation is usually complicated and time-consuming, and thus may delay the cutting process or a subsequent printing process.